What does getCurrentPosition return? - javascript

This is what I have:
var position;
navigator.geolocation.getCurrentPosition(onSuccess, onError);
function onSuccess(pos) {
position = { latitude: pos.coords.latitude, longitude: pos.coords.longitude} ;
//position = { latitude:43.465099,longitude:-80.520344};
}
function onError(error) {
alert('code: ' + error.code + '\n' +
'message: ' + error.message + '\n');
}
var myOptions = {
center: new google.maps.LatLng(
position.latitude,position.longitude
),
zoom: 14,
mapTypeId: google.maps.MapTypeId.ROADMAP,
disableDefaultUI: true
};
When I use the commented out line, the program works fine and it zooms to the hardcoded location. When I use the pos.coords line, nothing happens. Am I calling it wrong? Am I not able to just put it in my variable like that or does it return something else?

You appear to be using the result properly but I would encode the JSON a bit differently:
position = { "latitude": pos.coords.latitude,
"longitude": pos.coords.longitude};

Related

How to pan on google maps?

I'm working on simple App which provide for our clients our branches location, I use now a snapshot of the map, but I want to show the location on real map (Pan) not just an image.
I use Intel XDK platform (HTML/Javascribt)
This is the code I use:
function onError(error) {
alert('code: ' + error.code + '\n' +
'message: ' + error.message + '\n');
}
var output = document.getElementById("mapp");
function success(position) {
var latitude = position.coords.latitude;
var longitude = position.coords.longitude;
output.innerHTML = '<p>Latitude is ' + latitude + '° <br>Longitude is ' + longitude + '°</p>';
var img = new Image();
img.src = "https://maps.googleapis.com/maps/api/staticmap?center=" + latitude + "," + longitude + "&zoom=13&size=400x400&sensor=false";
output.appendChild(img);
};
output.innerHTML = "<p>Locating…</p>";
navigator.geolocation.getCurrentPosition(success, onError);
I found the answer, just by changing success function to:
var latitude = position.coords.latitude;
var longitude = position.coords.longitude;
var bangalore = { lat: 12.97, lng: 77.59 };
var map = new google.maps.Map(document.getElementById('mapp'), {
zoom: 14,
center: bangalore
});
var beachMarker = new google.maps.Marker({
position: bangalore,
map: map,
});

Proper formatting and distribution on multiple events for a jquery button click?

For now, on a button click I have it so that it takes in data from two textboxes, and uses it to
1) append tweets to a panel, and
2) drop pins on a map.
My next step is to have it so that on the button click, it geodecodes a location, and does the same thing. I feel like my jquery.click function is getting really big, and wanted to know if there was a standard way to "separate" it out to make it look prettier and more readable. Can you typically have javascript functions within a jquery file that are called upon, or what is the way to go?
Here is my current jquery file. As you can see it's very big but what happens is straight forward: searchbutton on click takes some values, and sets up a new map in that location, then I access my web server's information, append it to a panel, and also drop pins on a map.
$(function () {
$("#search-button").click(function() {
// variables for google maps
var LatValue = parseFloat($("#searchLat").val());
var LonValue = parseFloat($("#searchLon").val());
var myLatLng = {lat: LatValue, lng: LonValue};
var map = new google.maps.Map(document.getElementById('map-canvas'), {
zoom: 12,
center: myLatLng
});
$.getJSON(
"http://localhost:3000/tw",
{
geoSearchWord: $("#searchme").val(),
geoSearchWordLat: $("#searchLat").val(),
geoSearchWordLon: $("#searchLon").val(),
geoSearchWordRad: $("#searchRadius").val()
}
).done(function (result) {
$("#fromTweets").empty();
console.log(result);
for (i = 0; i < result.statuses.length; i++) {
//Print out username and status
$("#fromTweets").append('<b>' + "Username: " + '</b>' + result.statuses[i].user.screen_name + '<br/>');
$("#fromTweets").append('<b>' + "Tweet: " + '</b>' + result.statuses[i].text + '<br/>');
$("#fromTweets").append('<b>' + "Created at: " + '</b>' + result.statuses[i].created_at + '<br/>');
if (result.statuses[i].geo !== null) {
//Print out the geolocation
$("#fromTweets").append('<b>' + "GeoLocation: " + '</b>' + "Lat: " + result.statuses[i].geo.coordinates[0] + " Lon: " + result.statuses[i].geo.coordinates[1] + '<br/>'+ '<br/>');
//dropping a new marker on the map for each tweet that has lat/lon values
//Multiplying by i * 0.0005 to space them out in case they are from the same gelocation while still holding
//the integrity of their location.
LatValue = parseFloat(result.statuses[i].geo.coordinates[0] + i*0.0005);
LonValue = parseFloat(result.statuses[i].geo.coordinates[1] + i*0.0005);
myLatLng = {lat: LatValue, lng: LonValue};
var newMarker = new google.maps.Marker({
position: myLatLng,
map: map,
animation: google.maps.Animation.DROP,
});
} else {
$("#fromTweets").append('<b>' + "GeoLocation: " + '</b>' + "Cannot be identified" + '<br/>' + '<br/>')
}
}
});
});
The most simple and obvious thing you can do it so split your code by extracting independent logical blocks to functions:
Just something like this:
var map;
function combineTweetsAjaxRequestData()
{
return {
geoSearchWord: $("#searchme").val(),
geoSearchWordLat: $("#searchLat").val(),
geoSearchWordLon: $("#searchLon").val(),
geoSearchWordRad: $("#searchRadius").val()
};
}
function createGMap()
{
return new google.maps.Map(document.getElementById('map-canvas'), {
zoom: 12,
center: {
lat: parseFloat($("#searchLat").val()),
lng: parseFloat($("#searchLon").val())
}
});
}
function createGMarker(coords)
{
var coordsFixed = {
lat: parseFloat(coords[0] + i * 0.0005),
lng: parseFloat(coords[1] + i * 0.0005)
};
return new google.maps.Marker({
position: coordsFixed,
map: map,
animation: google.maps.Animation.DROP,
});
}
function clearInfo() {
$("#fromTweets").empty();
}
function appendInfo(title, text)
{
$("#fromTweets").append('<b>' + title + ':</b> ' + text + '<br/>');
}
function processTweet(tw)
{
appendInfo('Username', tw.user.screen_name);
appendInfo('Tweet', tw.text);
appendInfo('Created at', tw.created_at);
if (tw.geo !== null) {
var twCoords = tw.geo.coordinates;
appendInfo('GeoLocation', "Lat: " + twCoords[0] + " Lon: " + twCoords[1]);
createGMarker(twCoords);
} else {
appendInfo('GeoLocation', "Cannot be identified")
}
}
function loadTweets() {
$.getJSON(
"http://localhost:3000/tw",
combineTweetsAjaxRequestData()
).done(function (result) {
clearInfo();
console.log(result);
result.statuses.forEach(processTweet);
});
}
$(document).ready(function () {
map = createGMap();
$("#search-button").click(function() {
loadTweets();
});
});
Now, it can be easily read as a text. Your code should be readable and understandable from the first glance. Even better, if a non-developer can read it and understand some basic concepts.
What happens when the page is loaded? We create a Google map control and load tweets
How do we load tweets? We make a AJAX request by combining request data from inputs
What happens when it is loaded? We clear out current information and process every tweet
How do we process a single tweet? We output some basic information. Then, we output geolocation if it is available. Otherwise, we output an error.
Now, if you need to add information to another source, you won't extend or modify your loadTweets method - you will extend or modify appendInfo method, because the logics of information output is encapsulated here.

Google Maps is grey after being called a second time

I am looping through some JSON files and using the address from the JSON file for the google maps. I know the address is working properly because I set an alert to show the variable and it's showing what I expect. The call for the map is inside a click function. on one virtual page I have a list of customers and when the user clicks that customer, it redirects to another virtual page to display that customers information, with a map showing their address. When I do this for the first time , it works. If I click back, then select a different customer the map is just grey. Any idea why this is happening?
Here is my click function..
function cHandle(num) {
$("#custSpan" + i).on("click", function () {
window.location.href = "#CustInv";
custName = customer.Customer[num].compName;
$("#CustInvHead").html(custName);
$("#invoiceh2").html(custName + "'s Invoices");
$("#custInfo").empty();
$("#invoice").empty();
$("#map-canvas").empty();
var inc = customer.Customer[num].compId;
$("#custInfo").append("Customer ID: " + customer.Customer[num].compId + "<br /><br />"
+"Customer Name: " + custName + "<br /><br />"
+"Customer Address: " + customer.Customer[num].compAddress + "<br /><br />"
+"Customer Contact: " + customer.Customer[num].compContact + "<br /><br />"
+"Customer Phone: " + customer.Customer[num].compPhone + "<br/ ><br />"
+ "Customer Email: " + customer.Customer[num].compEmail + ""
);
address = customer.Customer[num].compAddress;
//alert(address);
codeAddress();
})
}
cHandle(i);
And here is my maps stuff..
function success(pos) {
lat = pos.coords.latitude;
lng = pos.coords.longitude;
drawMap();
}
function error(err) {
alert("Error " + err.code + " : " + err.message);
}
;
function codeAddress() {
lat = 0;
lng = 0;
//Get the address
//address = "123 Fake St";
if (address == "") {
alert("No Address Entered");
return;
}
//Change address to coordinates to plot on map
else {
geocoder = new google.maps.Geocoder();
geocoder.geocode({ 'address': address }, function (results, status) {
if (status == google.maps.GeocoderStatus.OK) {
var myLatLng = results[0].geometry.location;
lat = results[0].geometry.location.lat();
lng = results[0].geometry.location.lng();
drawMap();
}
else {
alert("Geocode was not successful for the following reason: " + status);
return;
}
})
}
}
function drawMap() {
mapCenter = new google.maps.LatLng(lat, lng);
var mapOptions = {
center: mapCenter,
zoom: 18,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
//Display the address
var map = new google.maps.Map(document.getElementById("map-canvas"), mapOptions);
//Map Marker
var myLoc = new google.maps.Marker({
map: map,
animation: google.maps.Animation.DROP,
position: mapCenter
});
You call several times the creation of the map as you should call once (Initialize) map and call several times the function of creating the marker.
split the code in drawMap in two
first declare the var map at top (window) level (outside the functions)
and initialize your map
var map
function initialize() {
mapCenter = new google.maps.LatLng(lat, lng);
var mapOptions = {
center: mapCenter,
zoom: 18,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
//Display the address
map = new google.maps.Map(document.getElementById("map-canvas"), mapOptions);
google.maps.event.addDomListener(window, 'load', initialize);
</script>
second in the codeAddress() function call only the create marker function
function createMarker() {
var myLoc = new google.maps.Marker({
map: map,
animation: google.maps.Animation.DROP,
position: mapCenter
});
}

How to save a variable value outside of a function in javascript

I am newbie to JavaScript, I was trying to make a simple GoogleMaps which is centered in my current position and I am finding problems saving my latitude and longitude to center the map.
Here is my code which i have adopted:
function initialize() {
var latitudeCenter;
var longitudeCenter;
navigator.geolocation.getCurrentPosition(onSuccess, onError);
function onSuccess(position){
console.log(position.coords.latitude, position.coords.longitude);
latitudeCenter = position.coords.latitude;
longitudeCenter = position.coords.longitude;
}
function onError(error){
alert('Error en GPS: ' + error);
}
var mapOptions = {
zoom: 8,
center: new google.maps.LatLng(latitudeCenter, longitudeCenter)
};
map = new google.maps.Map(document.getElementById('map-canvas'),mapOptions);
console.log('latitud: ' + latitudeCenter + ' longitud: ' + longitudeCenter);
}
In the first console log I can read my current position and latitude, so that method works fine, but when I try to save it in centerLatitude and centerLongitude it does not work, it displays undefined.
Thanks for the help
So, the functions onSuccess and onError are asynchronous, so you won't get back an answer straight away. So therefore you put your actual map initialisation code inside that onSuccess
function initialize() {
var latitudeCenter;
var longitudeCenter;
navigator.geolocation.getCurrentPosition(onSuccess, onError);
function onSuccess(position){
console.log(position.coords.latitude, position.coords.longitude);
latitudeCenter = position.coords.latitude;
longitudeCenter = position.coords.longitude;
var mapOptions = {
zoom: 8,
center: new google.maps.LatLng(latitudeCenter, longitudeCenter)
};
map = new google.maps.Map(document.getElementById('map-canvas'),mapOptions);
}
function onError(error){
alert('Error en GPS: ' + error);
}
console.log('latitud: ' + latitudeCenter + ' longitud: ' + longitudeCenter);
}

Javascript shows only last markers

The following code grabs some JSON data from /home.json URL which contain 5 microposts by 6 users. However, only the last 4 markers are shown (not even the 5th !!). I have spend 2 days to find the bug but unfortunately I can't really get why this dosen't work. If anyone could help me I would really appreciate it!
I have tested all lon/Lat variables through alert! All of them have the appropriate data. The map should be ok since the last 4 are shown !! Most probably the problem lies with my closure definition but I really cannot understand what I am doing wrong..
var GMAPS = window.GMAPS || {};
GMAPS.mainMap = function() {
var map;
var infowindow = new google.maps.InfoWindow();
var jsonObject = {};
function addMarkers() {
var xhr = new XMLHttpRequest();
xhr.open( "GET", "/home.json", true );
xhr.onreadystatechange = function () {
if ( xhr.readyState == 4 && xhr.status == 200 ) {
jsonObject = JSON.parse( xhr.responseText );
for (var i=0; i<jsonObject.length; i++) {
for (var j=0; j<jsonObject[i].microposts.length; j++) {
(function(Name, Title, Content, Latitude, Longitude) {
return function() {
//alert(Name + "\n" + Title + "\n" + Content + "\n" + Latitude + "\n" + Longitude + "\n"); //<-- this works!
var position = new google.maps.LatLng(Latitude, Longitude);
var contentString = "<h4>" + Name.bold() + "</h4>" + "<br />" + Title.bold()
+ "<br />" + Content;
var marker = new google.maps.Marker({
position: position,
title: Title,
map: map
});
google.maps.event.addListener(marker, 'click', (function(marker, contentString) {
return function() {
infowindow.setContent(contentString);
infowindow.open(map, marker);
}
})(marker, contentString));
};
})(jsonObject[i].name, jsonObject[i].microposts[j].title,
jsonObject[i].microposts[j].content,
jsonObject[i].microposts[j].lat,
jsonObject[i].microposts[j].lon)();
}
}
}
};
xhr.send(null);
}
function createMap() {
map = new google.maps.Map(document.getElementById('main_map'), {
zoom: 10,
panControl: true,
zoomControl: true,
zoomControlOptions: {
style: google.maps.ZoomControlStyle.SMALL
},
mapTypeControl: true,
scaleControl: true,
streetViewControl: true,
overviewMapControl: true,
scrollwheel: false,
center: new google.maps.LatLng(37.975327,23.728701),
mapTypeId: google.maps.MapTypeId.ROADMAP
});
}
function initAddress() {
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(showPosition);
}
else {
var position = new google.maps.LatLng(0, 0);
map.setCenter(position);
}
}
function showPosition(position) {
var position = new google.maps.LatLng(position.coords.latitude, position.coords.longitude);
map.setCenter(position);
}
return {
initMap : function() {
createMap();
initAddress();
addMarkers();
}
};
}();
document.addEventListener("DOMContentLoaded", GMAPS.mainMap.initMap, false);
** Note: you have an unnecessary extra set of parens at the end of your IIFE.
Before your IIFE (inside the innermost for-loop), try adding:
var jObj = jsonObject[i], mPost = jObj.microposts[j];
Then in replace the arguments to the IIFE with:
(function(Name, Title, Content, Latitude, Longitude) {
return function() {
//alert(Name + "\n" + Title + "\n" + Content + "\n" + Latitude + "\n" + Longitude + "\n"); //<-- this works!
var position = new google.maps.LatLng(Latitude, Longitude);
var contentString = "<h4>" + Name.bold() + "</h4>" + "<br />" + Title.bold()
+ "<br />" + Content;
var marker = new google.maps.Marker({
position: position,
title: Title,
map: map
});
google.maps.event.addListener(marker, 'click', (function(marker, contentString) {
return function() {
infowindow.setContent(contentString);
infowindow.open(map, marker);
}
})(marker, contentString));
};
})(jObj.name, mPost.title, mPost.content, mPost.lat, mPost.lon);
The following code should work. I still don't understand why you have the extra set of parentheses.
xhr.onreadystatechange = function() {
var i = 0, j = 0;
if ( xhr.readyState == 4 && xhr.status == 200 ) {
jsonObject = JSON.parse( xhr.responseText );
for (var ilen = jsonObject.length; i < ilen;) {
for (var jObj = jsonObject[i++], jlen = jObj.microposts.length; j < jlen;) {
var mPost = jObj.microposts[j++];
(function(Name, Title, Content, Latitude, Longitude) {
return function() {
//alert(Name + "\n" + Title + "\n" + Content + "\n" + Latitude + "\n" + Longitude + "\n"); //<-- this works!
var position = new google.maps.LatLng(Latitude, Longitude);
var contentString = "<h4>" + Name.bold() + "</h4>" + "<br />" + Title.bold()
+ "<br />" + Content;
var marker = new google.maps.Marker({
position: position,
title: Title,
map: map
});
google.maps.event.addListener(marker, 'click', (function(marker, contentString) {
return function() {
infowindow.setContent(contentString);
infowindow.open(map, marker);
}
})(marker, contentString));
};
})(
jObj.name, mPost.title, mPost.content, mPost.lat, mPost.lon
);
}
}
}
};

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